Referring to a figure

I’m writing a paper that has a number of figures that compare two images, and I’m constantly debating whether it’s necessary to repeat the figure number when I compare those images in the text.

For instance, if I write “the object on the right in Figure 1 is an abstract version of the object on the left,” is it necessary to write “on the left in Figure 1,” “in that figure,” or “in the same figure?” Or is it obvious that I’m talking about Figure 1?